The present invention relates in general to a device for preventing foreign matter from being sucked into a gas turbine engine, and more particularly, to improvements in such a device of deflector type.
Generally, a helicopter would often make a flight at a low speed, and it would often encounter a freezing weather as in a falling snow or in a cloud in winter. In such a case, sometimes, a front surface of an aircraft body may become icebound as shown at (a) in FIG. 1, and ice flakes are peeled off and sucked into a gas turbine engine (b), whereby an engine compressor may be damaged and the engine (b) may flame out. Consequently, regardless of whether it is for military use of for civil use, the employment of a helicopter in winter has been extremely limited, and this is a serious problem for a helicopter that is required to have an all-weather nature as is the case with rescue, anti-submarine operation, etc.
In order to resolve the aforementioned problem, various types of devices for preventing foreign matter from being sucked into a gas turbine engine of a helicopter have been heretofore developed. Wire gauze particle separator and deflector type prevention devices are known. However, the wire gauze type of device has a disadvantage that as a result of blocking of the mesh of the wire gauze by freezing the intake air of the engine might be possibly choked. Also the particle separator type of device has a disadvantage that the structure is complex and heavy in weight, and that under a freezing weather condition it is not practically useful, similarly to the wire gauze type of device. Still further, the conventional deflector type of device in which a deflector is fixedly mounted has a disadvantage that as a result of deflection of the intake air flow for the engine, the air intake efficiency of the engine is lowered, and thereby an engine output is lowered and a fuel consumption rate of the engine is increased.